From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23E1FC433EF for ; Fri, 20 May 2022 18:37:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352885AbiETSha (ORCPT ); Fri, 20 May 2022 14:37:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58814 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352892AbiETSh2 (ORCPT ); Fri, 20 May 2022 14:37:28 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6995D17997E for ; Fri, 20 May 2022 11:37:27 -0700 (PDT) Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 24KHSaaf019996 for ; Fri, 20 May 2022 11:37:27 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=3zHDjbn72NXSBweb9g6a0xThug/NIwNbovojkJVDB2M=; b=KlpcVBpG1o56WU6V/9+d3pMGsk6wUOQrEUofWrF5HnYQnK+igDdtOfqmgUe0JgLP8v37 MAMknrlhstM4JbckkOK8j7n1/XC39hht0HQCqVO5CgGTmcr61zBzbYzfCtY2rddzpo9p NOgTlVSCNxsibeUh0VAS6sCxAh1Sh1WpUcc= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3g60bnn9fs-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 20 May 2022 11:37:27 -0700 Received: from twshared14818.18.frc3.facebook.com (2620:10d:c085:108::8) by mail.thefacebook.com (2620:10d:c085:21d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Fri, 20 May 2022 11:37:26 -0700 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id 61888F5E5B21; Fri, 20 May 2022 11:37:16 -0700 (PDT) From: Stefan Roesch To: , , , , CC: , , , Subject: [RFC PATCH v4 01/17] mm: Move starting of background writeback into the main balancing loop Date: Fri, 20 May 2022 11:36:30 -0700 Message-ID: <20220520183646.2002023-2-shr@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220520183646.2002023-1-shr@fb.com> References: <20220520183646.2002023-1-shr@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-ORIG-GUID: Tb02OeAE_8Ibc885Kh_cPwVn8XHCUAk7 X-Proofpoint-GUID: Tb02OeAE_8Ibc885Kh_cPwVn8XHCUAk7 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.874,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-05-20_06,2022-05-20_02,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org From: Jan Kara We start background writeback if we are over background threshold after exiting the main loop in balance_dirty_pages(). This may result in basing the decision on already stale values (we may have slept for significant amount of time) and it is also inconvenient for refactoring needed for async dirty throttling. Move the check into the main waiting loop. Signed-off-by: Jan Kara Signed-off-by: Stefan Roesch --- mm/page-writeback.c | 31 ++++++++++++++----------------- 1 file changed, 14 insertions(+), 17 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 7e2da284e427..8e5e003f0093 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1618,6 +1618,19 @@ static void balance_dirty_pages(struct bdi_writeba= ck *wb, } } =20 + /* + * In laptop mode, we wait until hitting the higher threshold + * before starting background writeout, and then write out all + * the way down to the lower threshold. So slow writers cause + * minimal disk activity. + * + * In normal mode, we start background writeout at the lower + * background_thresh, to keep the amount of dirty memory low. + */ + if (!laptop_mode && nr_reclaimable > gdtc->bg_thresh && + !writeback_in_progress(wb)) + wb_start_background_writeback(wb); + /* * Throttle it only when the background writeback cannot * catch-up. This avoids (excessively) small writeouts @@ -1648,6 +1661,7 @@ static void balance_dirty_pages(struct bdi_writebac= k *wb, break; } =20 + /* Start writeback even when in laptop mode */ if (unlikely(!writeback_in_progress(wb))) wb_start_background_writeback(wb); =20 @@ -1814,23 +1828,6 @@ static void balance_dirty_pages(struct bdi_writeba= ck *wb, =20 if (!dirty_exceeded && wb->dirty_exceeded) wb->dirty_exceeded =3D 0; - - if (writeback_in_progress(wb)) - return; - - /* - * In laptop mode, we wait until hitting the higher threshold before - * starting background writeout, and then write out all the way down - * to the lower threshold. So slow writers cause minimal disk activity= . - * - * In normal mode, we start background writeout at the lower - * background_thresh, to keep the amount of dirty memory low. - */ - if (laptop_mode) - return; - - if (nr_reclaimable > gdtc->bg_thresh) - wb_start_background_writeback(wb); } =20 static DEFINE_PER_CPU(int, bdp_ratelimits); --=20 2.30.2